Clutching mechanism.



N. LOMBARD.

v CLUTCHING MECHANISM. APPLICATION men JAN. 19.1916. RENEWED APR. 26. 19W.

1,270,533. PilitllttdJklIH 25, 1918.

na'rnanim. tomnann, or woncns'rnia, massacnusn'rrs, assxcnon. 'ro ncmnann canscanron comramr, or Woncnsrnn, nassacnussr'rs, a oonrona'rmn or MASShCHUSETTS.

emmas.

GLUTGHING MECHANISM.

specification of Letters latent. Patented June 25, 1918.

Application filed January is, 1916, Serial m. 73,049. aenewea s ruce, 1918. Serial No. 231,023.

To all whom it may concern:

Be it known that I, NATHANIEL Loianarn, a citizen of the United States, residing at Vvorcester, in the county of Worcester and' between two members of such a mechanism,

which are adapted to rotate in unison, is cf.- fected with the minimum of friction between said parts, thereby greatly increasing the smoothness of action and the certainty of performance of a clutching device, as hereinafter particu larl set forth.

, In the accompanying drawings I have illustrated my invention in connection with the well known type of friction or cone clutch commonly used in motor vehicles, to which my improvement is peculiarly applicable; it is to be understood, however, that the showing and description herein are merely illustrative, and that my invention is equally applicable to other types of clutches and power transmitting devices.

In said drawings,

Figure 1 is a vertical sectional view of a clutching mechanism embodying my invention.

Fig. 2 is a fragmentary section, on the line, "2 of Fig. 1.

F'g.-3 is a fragmentary view in side elevation of the axially 1novahle parts with which my invention is particularly concerncd.

Like reference characters refer to like parts in the different figures.

is As shown in thc'drawings-the motor vehicle clutching. mechanism, which I have chosen for the purpose of illustrating my invent-Lion, consists of the usual annular driving; member 1, directly connected to the enthe' empire." 'Tlie' driven shaft fifbywhich stransmittedf tov the driving urnaled at its forward end in a deal zinc shaft '2 and serving-as the; flywheel for e vehicle in i the' fwell known.

.. 3 rec ivin member 1,

' as usuall contemplated in devices ofthis' class. T e driven shaft 3 carries a longitudinally slidable plate or spider 5 which provides a peripheral friction surface (5 for cooperation with the inner peripheral friction surface 7 of the annular driving memher 1. A spring, retained by a fixed collar 9 on theshaft3, normally maintains the. plate 5 at the limit of its forward movement on the shaft 3, thus pressing the surfaces 6 a5 and 7 into close frictional contactand causing the rotation of the-driving member 1. to

be transmitted through the plate 5 to the dr ven shaft 3. The plate 5 provides an annular groove '10 for engagement by the usual pedal operated devices, not shown, by means of \vhichsaid plate'may be retracted against the pressure of the spring 8 to dis connect the friction surfaces 6 and 7 and thereby render the clutch inoperative. When these pedal operated devices arereleased, the

spring 8 again becomes effective to slide the has been obtained, and this construction has also afforded the relative longitudinal or axlal movement of said hub and plate \vithout permitting relative rotation between said )arts. However, it has been found that the a ove described connection, usually em-q bodied in a square or hexagonal shaft section, gives rise to considerable friction, neces- 9h,

sitatiug thc use of a very heavy spring 8 in order to insure the operative connection of the shaft 3 with the motor. Furtl-iermore, it

is apparent that with such a polygonal Eilltl'.

lng connection between the shaft. and the hub 11, theinitial engagement of the friction .surfaces 6 and 7, particularly when the clutch is being let in slowly, exerts an im- 'mediate'tendency to turn. the hub 11 on the 1 shaft; this torsional strain has. the effect of greatly increasing the sliding friction v be tween said hub and the squared or hexagonal v shaft section, since it forces the correspond ing surfaces thereof into closefrictionul co'ntact, with theapplication ofgreat pressure.[111ii By similarly shaping the 85 Asa consequence, the further forward movement of'the plate 5 to carry the surfaces 6 and 7 into complete engagement is met with considerable resistance; even with the use of 5 a very powerful spring 8, it is not an un-.

such a spring to let the clutch in slowly with the proper degree of smoothness. y my improved construction, there 1s contemplated a driving connection between the hub 11 and the shaft 3,'which will always insure rotation in unison of these parts 2 and, at the same time, permit relative longitudinal movement of said hub with the minimum of friction; furthermore, such a 1 connection as will cause the slight friction between the parts to be reduced, rather than increased, when an initialxtorsional strain is imparted to the plate 5 and its hub, thereby rendering impossible the sticking of said hu'bin The manner described above in connection with prior constructions. To this 85 end a sleeve 12 is interposed between the hub 11 and the shaft 3, said sleeve being of slightly less thickness than the annular space between said shaft and the bore of said hub. The slee e 12 carries a plurality of rows of anti-friction-balls 13- extending longitudinally thereof, said balls being preferably arranged and retained in} independent sockets 14, which are formed by holes bored through the wall of said sleeve for the insertion of said balls, after which the edges of said holes are upset as at 15,

a or otherwise flanged inwardly, to prevent the balls from being removed therefrom. The balls 13, as shown, are somewhat greater in diameter than the thickness of said sleeve so that their surfaces project beyond and. are exposed on both the inside and outside of the sleeve. The shaft 3 is formed ,with a plurality of longitudinal 56 grooves 16, corresponding in number to the rows of balls 13, and the side walls of each groove are suitably .shaped to provide a seat or raceway for the corresponding row of balls. The bore of the hub 11 provides 60 grooves 17 matching the grooves 16 of the shaft, so that each row of balls is effective with respect to a pair of corresponding raceways formed respectively in the shaft 3 and hub 11. i

It will thus be seen that, by the co6pera- 5 against the in Fig. 1.

tion of the several rows of balls 13 with the grooves 16 and 17 of the shaft "and hub respectively, said shaft and .hub are securely locked'together for rotation in unison, each row of balls, in the relation shown, constituting the equivalent of a key or spline. Furthermore, since each ball is in contact with the shaft 3 and hub 11 at two points only, the effective friction surface, when the plate 5 is moved longitudinally on the 7 shaft, is reduced to a minimum; in fact this friction becomes practically negligible. In the position shown in Fig. 1, the clutch has been disengaged, by retracting the plate orce of spring 8 in the usual 30 manner. When the spring becomes eflective to move the plate 5 forward, the hub 11 of they latter rolls on the balls 13 and said balls, in turn, roll in the grooves 16 of the shaft 3, it being evident that in the absence of slippage between the parts, said hub will travel twice as far as the sleeve 12 which carries the balls. Should-any slippage occur -between the parts, or should the normal relation existing therebetween be dist'urbed in-any manner,.the return of said parts to the exact position illustrated in Fig. 1, when,the clutch is disconnected, is insured by means of a stop or abutment 18 on the rear end of the sleeve 12, which is 96 in a position to be engaged by the end of hub 11 when said hub is drawn to the right Thus the displacement of the anti-friction element, embodied in the sleeve 12 and balls- 13,.is effectually prevented, since'theretrabtion of the. plate 5 always restores said anti-friction element to its normal position, irrespective of any conditions which may have arisen in the operation of the device to disturb or vary the relative positions of the parts. As shown in Fig. 3, the stop or abutment 18= preferably takes the form ,of a spring ring, adapted by its contractive force to become seated in a groove 19 formed near the end of sleeve 12. By thus making the" stop removable, the other parts of the clutch are enabled to be assembled in the usual manner.

Obviously the spring 8 used in connection with the clutch mechanism may be made extremely light. It will be apparent that when the clutch is .let in slowly, a very smooth action thereof is obtained, owing to the slight friction between the axially movable parts. lVhe'n a tor- 120 sional strain is set up in the plate 5 by the initial and incomplete engagement of the friction surfaces 6 and 7, the effective point contact of the balls 13 is practically halved, since all the strain comes on one 125 side thereof. Consequently the slight friction between the shaft 3 and hub 11 as carried by said balls is actually reduced, causing the further forward movement of the 7 plate 5, in carrying the friction int above described surfaces 6 ewness and 7 into complete contact, to be accomclutching mechanism operative or inoperapiished with the application of even less tive,and means coiiperating with said antispring pressure than when such torsional friction element to prevent relative rotalid straln had not occurred. Tl'rus it will be tional movement between said sections. seen that a clutch constructed in accordance 6. In mechanism of the character dc with my in ention is absolutely prevented scribed, a power transmission member comirom sticking,j and serves at alltimes to prising a pair of sections rotatable in unitransm t .the full power of the driving shaft son and adaptedfor relative longitudinal since ts complete engagement s absolutely movement, an anti-friction element disposed insured. It will be obv ous also that the :for rolling movementiwith respect to both results obtained, as stated above,flare possibie with the use of a much lighter spring relatively, and means for limiting the. travel than, ean be employed in the 11 0011- of said anti-friction element in one direcsirnctions, tion. T

lciaim, In Inechanism'of the character de- 19111. 1 lut h ng mechamsm, a ng scribed, a power transmission member cornmember and a dr ven member, one Of 31d prising a longitudinally fixed and a 'longimembers. comprising two sections adapted tudinally movable section, adapted for rota- "ion relative movement to render said clutchti i i thf i ti means i t 'ing mechanismop ra P posed between'said sections and in longiantidrict-iion element disposed f r r llmg tudinal rolling contact. with each, as said movement relativetoboth of said sections, movable section is moved, and means for en Same 3 moved relatively to B maintaining a predetermined relation beanother, forsaid anti-friction element, said guiding jmnans d th movement f id bl means cotiperating with said anti-friction cti I relativelyto the other section,- and an anti and. guiding means on each section tween the movement of said anti-friction element to constrain the rotation of said sections in unison.

2, In a clutching mechanism, a driving member and a driven member, one of said members comprising'a pair of sections capabie of relative-axial movement, means dis- 8. In mechanism of the character de-' scribed, a power transmission member comprising a longitudinally fixed and a longitudinal'iy movable sec ion, adapted for rotation in unison, -anti-friction means interposed between said sections and in longituthe other section being .tions, means for moving one of said sections relative to btilll of said sections when posed for rolling movement with respect dinal rolling contact with each, as said movto both, of said sections, when the same are able section is moved, and means for limitmoved relatively, and guiding means on each ing the longitudinal movement of said antisection" for's'aid rolling means, cotiperating' friction mean .1 i 3 therewith to'constrain the rotation of said 9." in mechanism of the character desections in unison. I scribed, a power transmission member com 3. In a clutching mechanism, adrivinggwprising alongit'udinally fixed and a longimember and a driven. member, one of said tudinally-movabie section, adapted for rotamembers being co: 'stitut-ed by a pair of relation in ,unison, anti-friction means intertively movable sections, and an antidriction posed between said sections and in longiineans interposed between said sections, said tudinal rolling contact with each. as said anti-friction means being disposed for rollmovable section is moved. and means for ining movemcnt on one of said sections, and snring the movement of said anti-friction disposed for rolling means to a predetermined position. when movenientflon said anti-friction; means said movable section is moved in one direc-' 4. In ai clutching mechanism, a driving tion. mcmben-and a driven member, one of said members being constituted by a pair of sections. means for moving one of Said sections scribed, a power transmission member comprising a pair of sections rotatable in unison and adapted for relative longitudinal friction element disposed for rolling move movement, and anti-friction means interment relative to both of said sections when posed between said sections and in longithe n'iovabie section is moved to render the itudinal rolling contact with each at a plucl'utchinig mechanism operative or inoperarality of opposing points, whereby a force five. tendin to produce relative rotation between one of said said parts to a lesser number of points.

member and a driven member, I

1'1. Ina clutching mechamsnna driving members being constituted by a pair of secrciatively to the other section, an anti-fricmembers comprising 3 telescoping sections tion element disposed for rolling movement capable of relative axial movement to renthe dcr said clutching mechanism operative or movable seclionxis moved to render the inoperative, said sections having matching 10. In mechanism of the character (10- In a clutching mechanism, a driving said sections transfers the friction between member and a driven member, one of said.

'dfsaid sections when the same are moved ion longitudinal grooves on their opposing surfaces, and balls interposed between; said sec- 7 tions for rolling movement in both of said grooves when relative axial movement between said sections is effected, said balls and grooves cooperating to prevent relative rotational movement between said sections.

I 12. In a mechanism of the character described, a powertransmission member comprising telescoping sections capable of relative axial movement, said sections having matching longitudinal grooves on their, op-

posing surfa'ces, balls interposed between said sections for rolling movement in the grooves of each section when relative axial movement between said sections is effected,

saidballs and grooves cooperating to prevent relative rotational movement between a said sections,- and a ball retaining member interposed between said sections and adapted to hold said balls in spaced relation.

NATHANIEL LOMBARD.

Witnesses: I

Pmwmm: COMBERBACH, NELLIE NVHALEN 

